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Questions tagged [pattern-matching]

160 questions
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What is the difference between `a[bc]d` (brackets) and `a{b,c}d` (braces)?

What is the difference between a[bc]d and a{b,c}d? Why do people use a{b,c}d when there is already a[bc]d?
Weijun Zhou
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How to grep MATCH colored input?

Say I have output from a command that is colorized for the terminal. I want to match any line that contains the color yellow. How can I do this in grep, eg: mycommand -itSomtimesPrintsLinesWithYellowColorCodes | grep -e "?????" Note: This is NOT…
Zombies
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Why does find not find my directory neither with -name nor with -regex

I have a directory ~/Documents/machine_learning_coursera/. The command find . -type d -name '^machine' does not find anything I also tried find . -type d -regextype posix-extended -regex '^machine' so as to match the the beginning of the string…
moth
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How do I print the last sequence of lines between a start and an end pattern?

Answers to this question: How to grep lines between start and end pattern? are not concerned with multiple sequences of lines which fall between the match patterns. Thus, for example, sed -n '/startpattern_here/,/endpattern_here/p' will print…
einpoklum
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3 answers

Using an if statement for a list of words

So I have a program (say, programA), that will give me an output, for example: yes, no, maybe, probably, possibly, impossible, banana. I want to make a script that will do something, whatever it is, based on that output. Let's say I only need to…
Lhakryma DL
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2 answers

Avoiding non-zero exit code when running `ls` using multiple patterns

Say I have two possible paths I want to list directories and files under on a Linux machine: /some/path1/ /some/path2/ If I do the following in tcsh, I get 0 exit code, if at least one of path1 or path2 exists: ls -d /some/{path1,path2}/* But if I…
shikhanshu
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4 answers

Write a function that checks if a string starts with or contains something

I want to write a function that checks if a given variable, say, var, starts with any of the words in a given list of strings. This list won't change. To instantiate, let's pretend that I want to check if var starts with aa, abc or 3@3. Moreover, I…
No Imaginatition
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1 answer

Is there a Unix command that searches for similar strings, based mostly on how they sound when spoken?

I have a file of names, and I want to search within it, not caring too much about whether I have spelled the name ( that I am searching for ) correctly. I know that grep has quite a bit of functionality to search for a whole slew of similar strings…
gabkdlly
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Is "warning: range of the form `[o-b]' is locale dependent" a bug in gawk 4.1.0?

While writing some awk code I was using the --lint option for gawk 4.1.0. To my surprise I get a warning warning: range of the form `[o-b]' is locale dependent but my code has only a foo-bar outside of a character class. Simplified example: {…
U. Windl
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1 answer

How to refer to matched groups in jq gsub?

Using jq, I want to search for a pattern via regex, and wrap the matched string with something like
tags $ echo "\"This is a valid json file"\" | jq '. | gsub("valid";"how_to_refer_to_matches";"i") - How to refer to the matched results in the…
Zeta.Investigator
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3 answers

How to match a literal string containing an unclosed quote with ripgrep?

I have a file that contains the some python code. There is a line that contains the following(including the quotes) 'hello "value"' I want to search 'hello "value" in the file. Notice the unclosed quote. I'm using ripgrep with the folowing…
Haris Muzaffar
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2 answers

Exclude patterns from glob match

My directory looks like this: $ ls total 0 -rw-r--r-- 1 user user 0 Jun 18 22:44 file0 -rw-r--r-- 1 user user 0 Jun 18 22:44 file1 -rw-r--r-- 1 user user 0 Jun 18 22:44 file2 -rw-r--r-- 1 user user 0 Jun 18 22:44 file3 -rw-r--r-- 1 user user 0 Jun…
rewire
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Extract subsequence corresponding to n:th pattern from a file

I have below data blocks (multiple) chr1.trna4 (17188416-17188486) Length: 71 bp Type: Gly Anticodon: CCC at 33-35 (17188448-17188450) Score: 78.3 HMM Sc=56.60 Sec struct Sc=21.70 * | * | * | * | * | * …
MO12
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9 answers

How to put text inside text automatically?

I need to put one text inside another text. 1) I have a file with list of input values: A1 B2 C3 D4 E5 I have a wrapper pattern which should contain the text: $wgSpecialPageLockdown['INPUT_COMES_HERE'] = array('sysop'); For each input value, a…
Lahor
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Using anchor ^ pattern when using less / search command

When navigating through Linux man pages, sometimes you need to query the meaning of flags like -p or -al in the man pages. The default text reader for man pages is less and I'm trying to use the / search to find the first occurrence from the commons…
Silver137
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